Adding more than one element at a time to a list generated with a loop in python

Question

I want to make a list like this:

[str(s),'Numpad{}'.format(s) for s in range(0,10)]

that produces:

['1' , 'Numpad1' , '2' , ... ]

Is there a syntactically allowable way to do this?

Yes, but what are you trying to do exactly? Maybe there is a better approach to your goal? — idjaw, Oct 06 '16 at 03:10
Please show your *expected* output, then optionally add *how* you want to use this — OneCricketeer, Oct 06 '16 at 03:12
Look at the duplicate I flagged. The first solution does what you want. Replace each lambda with what you are trying to do in your comprehension. So first lambda does a `str(s)`, second lambda does a `"Numpad{}".format(s)` — idjaw, Oct 06 '16 at 03:14
@AlexEshoo Why does it have to be a single line? Why is that important? — idjaw, Oct 06 '16 at 03:17

score 1 · Answer 1 · edited May 23 '17 at 10:27

1

I found a great solution to you question here on a question regarding flatting of lists.

import itertools
list(itertools.chain(*[[str(s),'Numpad{}'.format(s)] for s in range(1,10)]))

Here more elegant solution provided by tdelaney in the comments section:

list(itertools.chain.from_iterable([str(s),'Numpad{}'.format‌(s)] for s in range(0,10)))

edited May 23 '17 at 10:27

Community

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1

answered Oct 06 '16 at 03:19

tommy.carstensen

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You can slim that down a bit: `list(itertools.chain.from_iterable([str(s),'Numpad{}'.format(s)] for s in range(0,10)))` – tdelaney Oct 06 '16 at 03:22
nit: range(1, 11). Even though OP has range(0, 10), their output is starting at 1. – idjaw Oct 06 '16 at 03:23
Thanks @tdelaney! Thanks @idjaw! Fixed! – tommy.carstensen Oct 06 '16 at 03:24
@tommy.carstensen Made a mistake on my part. range(1, 11) to actually make it end at 10. :) – idjaw Oct 06 '16 at 03:24
The asker never mentioned, whether it should end with 9 or 10 :) – tommy.carstensen Oct 06 '16 at 03:25
@tommy.carstensen good point :) – idjaw Oct 06 '16 at 03:28

OneCricketeer · Answer 2 · 2016-10-06T03:15:49.680

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Use a tuple?

In [1]: [(str(s),'Numpad{}'.format(s)) for s in range(0,10)]
Out[1]:
[('0', 'Numpad0'),
 ('1', 'Numpad1'),
 ('2', 'Numpad2'),
 ('3', 'Numpad3'),
 ('4', 'Numpad4'),
 ('5', 'Numpad5'),
 ('6', 'Numpad6'),
 ('7', 'Numpad7'),
 ('8', 'Numpad8'),
 ('9', 'Numpad9')]

Iterate over that with

for (val, numpad) in lst:

edited Oct 06 '16 at 03:15

answered Oct 06 '16 at 03:14

OneCricketeer

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Not really what I want since I don't want to search for tuples – Alex Oct 06 '16 at 03:15
Well, you didn't say anything about searching – OneCricketeer Oct 06 '16 at 03:16
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@AlexEshoo I think you should provide more information in your question on what you are trying to achieve so readers can know how to give you a good solution with *all* the necessary information. – idjaw Oct 06 '16 at 03:17

Adding more than one element at a time to a list generated with a loop in python

2 Answers2